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Date:   Tue, 22 Feb 2022 21:21:57 -0800
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Subject: [RFC PATCH 21/47] mm: asi: Add support for locally non-sensitive
 VM_USERMAP pages
From:   Junaid Shahid <junaids@google.com>
To:     linux-kernel@vger.kernel.org
Cc:     kvm@vger.kernel.org, pbonzini@redhat.com, jmattson@google.com,
        pjt@google.com, oweisse@google.com, alexandre.chartre@oracle.com,
        rppt@linux.ibm.com, dave.hansen@linux.intel.com,
        peterz@infradead.org, tglx@linutronix.de, luto@kernel.org,
        linux-mm@kvack.org
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Precedence: bulk

VM_USERMAP pages can be mapped into userspace, which would overwrite
the asi_mm field, so we restore that field when freeing these pages.

Signed-off-by: Junaid Shahid <junaids@google.com>


---
 mm/vmalloc.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index ea94d8a1e2e9..a89866a926f6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2424,6 +2424,14 @@ static void asi_unmap_vm_area(struct vm_struct *area)
 	 */
 	if (area->flags & (VM_GLOBAL_NONSENSITIVE | VM_LOCAL_NONSENSITIVE))
 		asi_unmap(area->asi, area->addr, get_vm_area_size(area), true);
+
+	if (area->flags & VM_USERMAP) {
+		uint i;
+
+		for (i = 0; i < area->nr_pages; i++)
+			if (PageLocalNonSensitive(area->pages[i]))
+				area->pages[i]->asi_mm = area->asi->mm;
+	}
 }
 
 #else
-- 
2.35.1.473.g83b2b277ed-goog